Environmental Engineering Reference
In-Depth Information
Production of
fruits and
vegetables
Grading, including
sorting, cleaning,
and packaging
RT
Harvesting
Precooling
RT
RT
Storage in refrigerated
warehouses
Consumers'
refrigerators
Grocery stores
Consumption
Postconsumption
Figure 3.8
Typical refrigerated supply chain for fruits and vegetables from production to postconsumption.
Solid lines with the RT indicate refrigerated transport.
Impact of consumption
In the end, consumers' choice is a pivotal aspect of sustainability including type of diet, life-
style, shopping behaviors, and living location. Diet selection makes a difference in the food
production's impact on the environment. By far, vegetarian diets are the ones with the least
impact on the environment. For the purpose of comparison, if the relative impact of a strictly
vegetarian diet is one, a lacto-ovo diet is six times, an average U.S. diet is eleven times, and a
100-percent meat only diet produces thirty-five times the impact of a vegetarian diet (United
Nations Environment Programme [UNEP], 2008).
Consumers make choices of food products that have little to do with nutrition but
instead with psychological gratification. Items such as beverages or candy are not choices
based normally on their nutritional value but personal enjoyment. Lifestyle plays an impor-
tant role on consumers' impact on the environment. The obesity epidemic that is taking
place in many countries is the result of excessive food consumption or excessive consump-
tion of high-calorie food and lack of exercise. For sure there are cases of obesity caused by
health issues; however, most of them are related to diet and lifestyle. Unnecessary food
consumption requires the production of additional food with the associated environmental
impact. In 2008, the average American consumed 2,673 kcal/day, which is an increase of
22 percent of the 2,187 kcal/day consumed in 1978 (United States Department of
Agriculture [USDA], 2010). The average energy allowance to keep a healthy weight ranges
between 2300 to 2900 kcal/day for males and 1900 to 2200 kcal/day for females (Whitney
and Rolfes, 2002).
Shopping habits produce different impacts. For instance, miles driven from home to the
grocery store and back produce an impact that is proportional to the distance driven and the
amount of food purchased in each trip (an analysis of this impact is presented in Chapter 13).
A concerned consumer would attempt to minimize the transportation impact by shopping less
often. But does this really minimize the overall impact? Not always. For instance, stocking
fresh food requires refrigeration and refrigerator efficiencies vary depending on the age and
technology of the equipment. Also, when buying lots of food, it is more likely to get spoiled
before it is consumed and that contributes to waste.
